Accurate structure factors and experimental charge densities from synchrotron X-ray powder diffraction data at...

Area of Science:

• Materials Science
• Crystallography
• Solid-State Physics

Background:

• Accurate determination of experimental charge density is crucial for understanding chemical bonding and material properties.
• Previous methods for determining charge density, such as the Pendellösung method, have limitations in terms of data quantity and applicability.

Purpose of the Study:

• To experimentally determine accurate structure factors for silicon and diamond using powder diffraction data.
• To evaluate the accuracy of structure factors obtained from powder diffraction by comparison with literature values and theoretical calculations.
• To obtain experimental charge densities and compare them with theoretical predictions.

Main Methods:

• Powder diffraction data collection at the SPring-8 synchrotron radiation source (BL02B2).
• Determination of structure factors from the diffraction data.
• Evaluation of structure factor accuracy against Pendellösung data and theoretical calculations.
• Calculation of experimental charge densities using the maximum-entropy method.

Main Results:

• Accurate structure factors for silicon (104) and diamond were determined.
• The obtained structure factors are sufficiently accurate for discussing experimental charge-density distributions.
• Experimental charge densities showed good agreement with various theoretical calculations.
• Powder diffraction at SPring-8 proved to be a viable method for experimental charge density determination.

Conclusions:

• Synchrotron powder diffraction is a powerful technique for obtaining accurate structure factors.
• The method enables the determination of experimental charge densities comparable to theoretical values.
• This approach is promising for a broader range of materials, advancing the field of experimental charge density studies.